The infrastructure requirements on telecommunications systems regarding availability are very high compared to other comparable systems. As the traffic through communications network Internet and other communications systems increases the power consumption increases. This increases the risk of, and the consequences of, a power failure.
It is common in the art to use fuses or protection switches to limit the damage caused by a power failure.
For example, the power supply to the electronic components is provided with fuses. For this purpose electromagnetic fuses are often used, because they are very reliable On the other hand, they are not optimal when the power consumption increases because of the transients caused by non-accurate tripping.
Electronic circuit breakers have the advantage that it is easier to avoid transients when breaking the current. Attempts to use electronic circuit breakers for protection switching of the power supplies in communication systems have been unsuccessful because they are not reliable enough.
As an example, the maximum acceptable failure rate λ at 44 A for the failure mode “short-circuit” is specified to 5 nF/h, where F/h is the acceptable number of failures per hour. This means that a maximum of 5×10−9 errors may occur per hour or, the other way around, that 2×108 hours should pass between errors. State of the art commercial semiconductors do not meet this rigorous reliability requirement. The failure rate for a single MOSFET is in the range of 20 nF/h. This means that a MOSFET has a far too high failure rate to be acceptable in applications having very high availability requirements.